1. Field of the Invention
The present invention relates to a composite employed to a semiconductor device or a display device, and more particularly, to a composite containing nano magnetic particles to exhibit such an electromagnetic characteristic as an ultra low dielectric constant.
2. Description of the Related Art
As an electromagnetic device, for example, a semiconductor device or a display device, has become highly integrated, it is necessary to employ a dielectric material having a relatively lower dielectric constant in such a device.
In more detail, in order to improve the performance of a semiconductor device or a display device or to enhance the integration level thereof, there has been a trend of sharply decreasing circuit interconnect line widths, which may increasingly bring about unacceptable interconnect resistance-capacitance (RC) delays. To solve this problem, it is required to reduce the dielectric constant of a dielectric material used as an insulating layer between interconnect lines. It is recognized that the RC delays reduce the operation speed of a semiconductor device, thus adversely affecting faster operation of the semiconductor device.
Accordingly, there have been various methods of forming an insulating layer using a dielectric material having a low dielectric constant, for example, poly(benzoxazole) having a structure similar to that of polyamide and a low dielectric constant and exhibiting a good thermal stability, as disclosed in EP 903639, EP 905170, EP 391200, EP 291779, EP 5123339, and EP 3716629. However, since poly(benzoxazole) has a poor photoactive property, it cannot be readily to be used as an interlayer dielectric (ILD) or an intermetal dielectric (IMD).
U.S. Pat. Nos. 5,114,780 and 5,115,082 disclose a dielectric material of fluorinated poly(acrylether) series, having a low dielectric constant of 2.6-2.7, which is however difficult to apply to a semiconductor manufacturing process due to its low glass transition temperature, that is, approximately 260° C. To overcome the application difficulty, an attempt to raise the glass transition temperature up to approximately 400° C. has been made. However, in this case the dielectric constant is undesirably increased to 2.8.
WO 97/10193 discloses an aromatic “SiLK” containing an orth-bisethynyl or -phenylethynyl group, exhibiting excellent thermal mechanical properties because of non-occurrence of a polar group or unsaturated structure after it is cured. However, the dielectric constant of the proposed material is kept at 2.6-2.7, and there is still a need to reduce the dielectric constant.
EP 0701283 A1 discloses a low dielectric material having a diamond-like structure of tetrahedral configuration of all carbon atoms contained therein, which is an inorganic material having excellent thermal and mechanical stability, compared to the earlier proposed low dielectric materials, which are generally organic materials having poor thermal mechanical stability. Nevertheless, in order to reduce the dielectric constant, which is still high due to the dielectric constant of diamond, that is, approximately 5.7, there has been an attempt to add hydrogen and fluorine, resulting in serious degradation of thermal stability.
U.S. Pat. Nos. 5,470,802, 5,494,858, 5,504,042, and 5,523,615 disclose methods for reducing a dielectric constant by introducing air pores (for air, k=1) into SiO2 or a polymer matrix such as polyamide. However, porous dielectrics based on the methods disclosed in the referenced patents have poor mechanical properties, a high hygroscopicity due to a high surface energy and a low dielectric strength.
As an ultra low dielectric constant material having a dielectric constant of 2.5 or less has been demanded for semiconductor device manufacturing processes, it has become necessary to develop a novel ultra low dielectric constant material that has a low dielectric constant, that is excellent in thermal and mechanical properties, has a low moisture absorbance, and has a high electric strength.